1. Field of the Invention
The invention relates to a method for producing metal foils by the foil-casting principle, comprising the steps of:                filling a casting frame with liquid metal;        moving a substrate through the bottom of the casting frame, the substrate being at a lower temperature than the melting point of the liquid metal, so that a bottom layer of the liquid metal crystallizes on the substrate, and a metal foil is formed on the substrate on one side of the casting frame.        
2. Description of the Related Art
DE 100 47 929 A1 describes a method in which the level of the liquid metal in the casting frame is measured with the aid of a float. If the level is too high, the pressure in the bottom of the casting frame can become so high that liquid metal escapes beneath the walls of the casting frame. As a result, lumps can form on the top surface of the foils, which has a significant adverse affect on the quality of the foils. In DE 100 47 929 A1, this problem is solved by controlling the level of the metal in the casting frame during the production process to below a maximum value. A desired thickness of the foils is achieved by optimally setting the length of the casting frame, the speed of a substrate belt and the temperature difference at the transition between the metal and the substrate belt. In this method, there is only a limited possibility of adjusting the thickness of the metal foils during the production process.